DAOS-16830 pool: Allow setting DAOS_POOL_RF to 0 (#15564) (#15692)

Since 0 is the minimum RF, we should allow setting it to 0. We can revisit naming later. Signed-off-by: Jeff Olivier <[email protected]>
daos-stack · Jan 9, 2025 · 32440e4 · 32440e4
1 parent cbe65ce
commit 32440e4
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diff --git a/docs/admin/env_variables.md b/docs/admin/env_variables.md
@@ -54,7 +54,7 @@ Environment variables in this section only apply to the server side.
 |DAOS\_DTX\_RPC\_HELPER\_THD|DTX RPC helper threshold. The valid range is [18, unlimited). The default value is 513.|
 |DAOS\_DTX\_BATCHED\_ULT\_MAX|The max count of DTX batched commit ULTs. The valid range is [0, unlimited). 0 means to commit DTX synchronously. The default value is 32.|
 |DAOS\_FORWARD\_NEIGHBOR|Set to enable I/O forwarding on neighbor xstream in the absence of helper threads.|
-|DAOS\_POOL\_RF|Redundancy factor for the pool. The valid range is [1, 4]. The default value is 2.|
+|DAOS\_POOL\_RF|Redundancy factor for the pool. The valid range is [0, 4]. The default value is 2.|
 
 ## Server and Client environment variables
 

diff --git a/src/pool/srv.c b/src/pool/srv.c
@@ -1,5 +1,5 @@
 /**
- * (C) Copyright 2016-2022 Intel Corporation.
+ * (C) Copyright 2016-2024 Intel Corporation.
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -21,10 +21,29 @@
 #include "srv_layout.h"
 
 bool		ec_agg_disabled;
-uint32_t	pw_rf; /* pool wise RF */
-#define PW_RF_DEFAULT	(2)
-#define PW_RF_MIN	(1)
-#define PW_RF_MAX	(4)
+uint32_t        pw_rf = -1; /* pool wise redundancy factor */
+#define PW_RF_DEFAULT (2)
+#define PW_RF_MIN     (0)
+#define PW_RF_MAX     (4)
+
+static inline bool
+check_pool_redundancy_factor(const char *variable)
+{
+	d_getenv_uint32_t(variable, &pw_rf);
+	if (pw_rf == -1)
+		return false;
+
+	D_INFO("Checked threshold %s=%d\n", variable, pw_rf);
+
+	if (pw_rf <= PW_RF_MAX)
+		return true;
+
+	D_INFO("pw_rf %d is out of range [%d, %d], take default %d\n", pw_rf, PW_RF_MIN, PW_RF_MAX,
+	       PW_RF_DEFAULT);
+	pw_rf = PW_RF_DEFAULT;
+
+	return true;
+}
 
 static int
 init(void)
@@ -52,14 +71,10 @@ init(void)
 	if (unlikely(ec_agg_disabled))
 		D_WARN("EC aggregation is disabled.\n");
 
-	pw_rf = PW_RF_DEFAULT;
-	d_getenv_uint32_t("DAOS_POOL_RF", &pw_rf);
-	if (pw_rf < PW_RF_MIN || pw_rf > PW_RF_MAX) {
-		D_INFO("pw_rf %d is out of range [%d, %d], take default %d\n",
-		       pw_rf, PW_RF_MIN, PW_RF_MAX, PW_RF_DEFAULT);
+	pw_rf = -1;
+	if (!check_pool_redundancy_factor("DAOS_POOL_RF"))
 		pw_rf = PW_RF_DEFAULT;
-	}
-	D_INFO("pool wise RF %d\n", pw_rf);
+	D_INFO("pool redundancy factor %d\n", pw_rf);
 
 	ds_pool_rsvc_class_register();